The present invention relates to a method of fabricating printed material for stereoscopic viewing, together with printed material for stereoscopic viewing.
A technique is known in the art of preparing an image for the left eye, taken by a camera that is equivalent to the left eye, and an image for the right eye, taken by a camera that is equivalent to the right eye, then combining these images by anaglyph processing or the like to obtain a stereoscopic image (printed material for stereoscopic viewing), as disclosed in Japanese Patent Laid-Open No. 2000-56411, by way of example.
There are three physiological functions that enable a human being to experience the feeling of three dimensions: (1) binocular parallax (difference in the line-of-sight angles thereof) that creates an offset in the imaging of the retinas due to the spatial separation of the left and right eyes, (2) convergence, which is a function that directs the eyes inward, and (3) focal adjustment (focal distance) of adjusting the thickness of the lens in answer to distance to the object. The human being processes the three physiological functions of binocular parallax, convergence, and focal adjustment within the brain, to produce the stereoscopic feeling.
The relationships between these three physiological functions are usually linked within the brain. If an error or inconsistency should arise in these relationships, therefore, the brain will try to force these stereoscopic linkages, which creates a situation in which the image feels unnatural or the viewer cannot recognize it as a stereoscopic image.
Incidentally, stereoscopic viewing in the prior art used only binocular parallax and convergence for representing a stereoscopic view. For that reason, the focus (focal distance) to any point within the surface of the stereoscopic image (printed material for stereoscopic viewing) remains substantially constant, so that offsets in binocular parallax or convergence occur at substantially all the locations in the stereoscopic image, making it impossible to implement a stereoscopic view that does not force the brain of a human being.